Dew on a spider web

Dew is water in the form of droplets that appears on thin, exposed objects in the morning or evening. As the exposed surface cools by radiating its heat, atmospheric moisture condenses at a rate greater than that of which it can evaporate, resulting in the formation of water droplets. Image File history File linksMetadata Download high resolution version (1200x808, 904 KB) Spider Web Covered with Dew Drops. ... Image File history File linksMetadata Download high resolution version (1200x808, 904 KB) Spider Web Covered with Dew Drops. ... Spider web with morning dew enhancing its visibility. ... Thermal radiation is electromagnetic radiation emitted from the surface of an object which is due to the objects temperature. ... Water vapor condensing over a cup of hot tea Condensation is the change in matter of a substance to a denser phase, such as a gas (or vapor) to a liquid. ... This article or section is in need of attention from an expert on the subject. ...

When temperatures are low enough, dew takes the form of ice; this form is called frost. Frost on black pipes Frost is a solid deposition of water vapor from saturated air. ...

Formation

The amount of water vapor air can hold depends on temperature. The temperature at which air is saturated with water vapor is called the Dew Point. When surface temperature drops, eventually reaching the dew point, atmospheric water vapor condenses to form small droplets on the surface. Fig. ... Dew on a spider web The dew point or dewpoint of a given parcel of air is the temperature to which the parcel must be cooled, at constant barometric pressure, for the water vapor component to condense into water, called dew. ...

Occurrence

Sufficient cooling of the surface typically takes place when it loses more energy by infrared radiation than it receives as solar radiation from the sun, which is especially the case on clear nights. [[ | Preferred objects of dew formation are thus poor conducting or well isolated from the ground, and non-metallic or coated as shiny metal surfaces are poor infrared radiators. Preferred weather conditions include the absence of clouds and little water vapor in the higher atmosphere to minimize greenhouse effects and sufficient humidity of the air near the ground. Image of two girls in mid-infrared (thermal) light (false color) Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. ... Radiation in physics is the process of emitting energy in the form of waves or particles. ... Solar irradiance spectrum at top of atmosphere. ...

 if the atmosphere is the major source of moisture (this part of dew is called dewfall), a certain amount of ventilation is needed to replace the vapor that is already condensed. The highest optimum wind speeds could be found on arid islands. 

Measurement

It has to be kept in mind that some of these methods include guttation, while others only measure dewfall and/or distillation. Guttation is the appearance of drops of water on the leaves of some vascular plants, such as grasses. ... Laboratory distillation set-up using, without a fractionating column 1: Heat source 2: Still pot 3: Still head 4: Thermometer/Boiling point temperature 5: Condenser 6: Cooling water in 7: Cooling water out 8: Distillate/receiving flask 9: Vacuum/gas inlet 10: Still receiver 11: Heat control 12: Stirrer speed...

Significance

Due to its dependence on radiation balance, dew amounts can reach a theoretical maximum of about 0.8 mm per night, measured values, however, rarely exceeding 0.5 mm. In most climates of the world, the annual average is too small to compete with rain.

In Greek mythology, Ersa is the goddess of dew. In Greek mythology, Ersa was the goddess of dew and a daughter of Zeus and Selene. ...

Artificial harvesting

Main article: Fog collection

At present, the International Organization for Dew Utilization is working on effective, foil-based condensers for regions where rain or fog cannot cover water needs throughout the year. To meet Wikipedias quality standards, this article or section may require cleanup. ...